Ethanol-gasoline Blends Research Articles

Corrosion analysis in the Al6061-T6 alloy exposed to anhydrous ethanol-gasoline blends using the Stockwell transform and the Shannon energy

The study of corrosion on aluminum alloys exposed to alternative fuels, such as ethanol, or bioethanol has been studied and presented in the literature by different researchers. Among signal processing methods reported in the literature can be found the statistical method (SM), the Fast Fourier Transform (FFT), and the Wavelet transform. In the present research, we focused on the corrosion analysis in aluminum proposing an alternative signal processing method (the Stockwell Transform (ST)) and using ethanol-gasoline blends. In this analysis, the metallic material used was aluminum alloy 6061-T6 (Al6061-T6). And the signal processing is carried out by the ST and Shannon energy (SSE) methods. The results showed an average corrosion rate of 3.25 × 10−7mm∕year and 3.81 × 10−4mm∕year in the Al6061-T6 exposed to E0 and E100, respectively. Highlighting that E10 and E20 produced lower corrosion effects, and E60, E80, and E100 caused the highest corrosion levels.

Blending of ethanol with gasoline and diesel fuel – A review

The blending of ethanol in gasoline and diesel engines is associated with several problems related to phase separation and volatility. However, ethanol up to 10% in a gasoline engine is commercialized, and several research is going on blending ethanol above 10% in a gasoline engine without modification. A high percentage of ethanol in gasoline engines requires modifications like a high compression ratio and cold start. In this study, a comprehensive study has been done on the stability of blends in ethanol–diesel and ethanol-gasoline engines. This study shows that ethanol in gasoline engines leads to phase separation due to the high affinity of ethanol for water and air humidity. Thus, the formation of an azeotropic mixture of the ethanol-gasoline blend. This study found that using ETBE and ethyl acetate can reduce the tendency of formation of azeotropic mixture and increase the water tolerance level. In addition, ethanol in a diesel engine is also studied and shows that a lower percentage of ethanol leads to reduced auto ignition time. However, nano additives like TiO2 and Al2O3 can increase BTE and reduce BSFC.

Performance, Combustion, and Emission Evaluation of Ethanol-Gasoline Blends Ignited by Diesel in Dual-Fuel Intelligent Charge Compression Ignition (ICCI) Engine

Abstract A recent proposed dual-fuel combustion mode, intelligent charge compression ignition (ICCI), realizes the high-efficiency and clean combustion by organizing continuous stratification in a wide range of engine load. The paper investigated the performance of alcohol blended gasoline as low-reactivity fuel (LRF) in ICCI combustion mode. Pure ethanol named E100 was also tested as LRF for comparison. To emphasize the differences of LRF properties and exclude the effect of the heat release phasing, the diesel injection timing was adjusted to maintain the same combustion phasing (CA50) at various LRF ratios under medium load. The results showed that E100 and E85 (ethanol ratio in gasoline-ethanol blend) promoted the degree of homogeneous combustion and eradicated soot emissions despite a slight increase of NOx. The maximum indicated thermal efficiency (ITE) was over 51.1% using E85, followed by 50.5% of E50. The perfect substitution ratio at the maximum ITE decreased from more than 80% to about 65% when increasing the ethanol ratio in LRF from 10% to 100%. The unregulated emissions such as aldehydes, ethylene, and methane, produced from incomplete combustion of ethanol were inhabited by E85, while the formation of toluene attributed to the appropriate carbon chain length of gasoline diminished when using E85 and E100.

Impact of 20% Ethanol-blended Gasoline (E20) on Metals and Non-metals used in Fuel-system Components of Vehicles

Ethanol is considered as a potential biofuel for blending with gasoline and, in India, it is planned to increase the ethanol content to 20 percent in gasoline by year 2025 from present allowable limit of maximum 10 percent. It is important to evaluate the impact of E20 fuel on the materials used in fuel-system components. An evaluation of 8 metals, 6 elastomers and 4 plastics used in various fuel-system components was conducted through systematic exercise of laboratory immersion following standard methods like SAE J1747 and SAE J 1748 with all the quality and quality assurance measures. The study was conducted with E20 as test fuel and commercial gasoline (BS IV) as a baseline fuel for comparative assessment. Impact of E20 on metals was evaluated through calculation of corrosion rates in mm/year based on data obtained for change in mass post-immersion in above fuels. Similarly, impact of elastomers and plastics was evaluated through observed changes in properties like mass, volume, tensile strength, elongation, impact strength and hardness. Impact of E20 on metals tested was found to be insignificant based on the corrosion rates. Polychloroprene, SBR, HNBR and Fluoroelastomer were found to perform similar or better in most of the properties with E20. Impact of E20 on NBR-PVC and Epichlorohydrin was more as compared to commercial gasoline. Similar changes in properties of PA12, PBT and Acetal were observed in both the fuels. Impact of E20 on tensile strength and volume change properties of PA66 was found to be more than commercial gasoline. The vital information generated can be utilised by design engineers for selection, modification of materials for various components of fuel-system of vehicles

Influence of injection pressure on performance and emission characteristics of single cylinder RCCI engine fuelled with ethanol gasoline and diesel biodiesel blends

Reactivity controlled compression ignition (RCCI) has great potential for a simultaneous reduction in Nitrogen oxides (NOx) and particulate matter (PM) with increase in thermal efficiency. In this experimentation, an attempt is made to investigate the effect of injection pressure on the performance emission and combustion characteristics of single cylinder RCCI engine. Literature reveals that injection pressure has a great influence on the quality of charge preparation, fuel stratification, and incylinder reactivity. Suitably modified engine was operated for 0 to 12 kg loads, for 400 to 700 injection pressure. The blend of ethanol gasoline E20 used as a low reactivity fuel and blend of diesel jatropha biodiesel B20 used as a high reactivity fuel. Experimental results showed that increase in injection pressure enhances the degree of charge homogeneity, reduces the combustion duration, and provides higher rate of energy release. For 12 kg load and 700 bar injection pressure, it is observed that 5% rise in thermal efficiency, 27% reduction in smoke opacity, 2% reduction in HC, 4% reduction in CO and 20% rise in NOx as compared to 400 bar injection pressure.

An equilibrium analysis of hydrogen production from ethanol-gasoline fuel blends reforming

A hydrogen concentration from ethanol-gasoline blends reforming processes plays a role in exhausted gas recirculation (EGR) that enhanced engine performance and aftertreatment system of gasoline direct injection (GDI) engine. An equilibrium model is widely used as a primary tool to determine a level of hydrogen content from reforming process. Thus, in this work, the equilibrium analysis of hydrogen production is investigated using STANJAN program. Three main reactions (Partial Oxidation Reforming (POx), steam reforming (SRM) and autothermal reforming (ATR)) are studied here. Three commercial ethanol-gasoline blends are studies here (E10, E20 and E85). The effect of reaction temperature, steam to fuel ratio (S/F) and oxygen to fuel ratios (O2/F) are investigated. The results show that the optimum condition for POx is achieved at O2/F ratio of 3 for E10 and E20 and 0.75 for E85. For SRM, the optimum condition for H2 production at temperature 200–500 °C are achieved with S/F ratio of 10–12 for E10 and E20, while E85 can be obtained at S/F ratio of 6–8. Under these conditions, the maximum hydrogen yield (∼30 vol%) are reached with temperature 500 °C. In case of ATR, the highest H2 yield (approximately 25 vol%) is achieved at temperature 500 °C with S/F ratio of 8 for E10 and E20 fuels and 4 for E85 fuel. The highest H2 yields from real exhausted gas reforming are 42 to 55 % vol. Thus, this possibility of on-board hydrogen production via gasoline - ethanol fuel blends reforming operates in GDI engine.

Implementation of Oxy-Fuel Combustion (OFC) Technology in a Gasoline Direct Injection (GDI) Engine Fueled with Gasoline-Ethanol Blends.

Nowadays, to mitigate the global warming problem, the requirement of carbon neutrality has become more urgent. Oxy-fuel combustion (OFC) has been proposed as a promising way of carbon capture and storage (CCS) to eliminate carbon dioxide (CO2) emissions. This article explores the implementation of OFC technology in a practical gasoline direct injection (GDI) engine fueled with gasoline–ethanol blends, including E0 (gasoline), E25 (25% ethanol, 75% is gasoline in mass fraction), and E50 (50% ethanol, 50% is gasoline in mass fraction). The results show that with a fixed spark timing, φCA50 (where 50% fuel is burned), of E50 and E25 is about 4.5 and 1.9° later than that of E0, respectively. Ignition delay (θF) and combustion duration (θC) can be extended with the increase of the ethanol fraction in the blended fuel. With the increase of the oxygen mass fraction (OMF) from 23.3 to 29%, equivalent brake-specific fuel consumption (BSFCE) has a benefit of 2.12, 1.65, and 1.51% for E0, E25, and E50, respectively. The corresponding increase in brake-specific oxygen consumption (BSOC) is 21.83, 22.42, and 22.58%, respectively. Meanwhile, θF, θC, and the heat release rate (HRR) are not strongly affected by the OMF. With the increase of the OMF, the increment of θF is 0.7, 1.8, and 2.2° for E0, E25, and E50, respectively. θC is only extended by 1, 1.1, and 1.4°, respectively. Besides, by increasing the intake temperature (TI) from 298 to 358 K under all of the fuel conditions, BSFCE and BSOC present slight growth trends; θF and θC are slightly reduced; in the meantime, φCA50, φPmax (crank angle of peak cylinder pressure), and the position of the HRR peak are advanced by nearly 1°.

Knock and knock intensity models for boosted SI conditions with gasoline-ethanol blends

In this work, a previously developed, two-stage table-lookup kinetic method for surrogate Toluene Reference Fuels (TRF) was extended to gasoline-ethanol blends and exercised in a GT-POWER model of knock in several engines. Experimentally, the knock limit is normally determined by the magnitude of pressure oscillations, known as the knock intensity (KI), rather than the crank angle of initial pressure oscillations or the crank angle of auto-ignition, which is difficult to identify. A number of empirical expressions of knock intensity have been developed for modeling purposes which relate the knock intensity to the crank angle and conditions at auto-ignition, and are available in the literature. These models were implemented into a GT-POWER model and tested against experimental knock-limited data for gasoline and gasoline-ethanol blends. The KI models are phenomenological in nature and are based on varying conceptual views of the knock event. With calibration all methods gave satisfactory results at mid-speed conditions when compared with the experimental data. Some deviations were seen at low and high speeds. Low speeds are potentially important because both RON and MON testing occurs under such conditions. Implications of the results and their relationship to recent knock experimental work are discussed and suggestions offered for improved knock models.

Preferential removal of benzene, toluene, ethylbenzene, and xylene (BTEX) by persulfate in ethanol-containing aquifer materials.

The effective approaches to eliminate impacts of ethanol on the biodegradation of benzene, toluene, ethylbenzene, and xylene (BTEX) are concerned in the bioremediation of groundwater contaminated with ethanol-blended gasoline. In situ chemical oxidation (ISCO) is a common technique widely used for the remediation of contaminated groundwater. However, the selectivity of ISCO for BTEX and ethanol removal is poorly understood. Therefore, a batch experiment was performed with different aquifer materials, including calcareous soil, basalt soil, granite soil, dolomite, and sand. Gasoline was used to provide dissolved BTEX and ethanol reagent was used as additive to improve the quality of gasoline and to reduce the possibility of air pollution caused by gasoline. Persulfate (PS) was used as a chemical oxidant to oxidize organic contaminants. The target concentrations of BTEX and ethanol were 20mg/L and 1000mg/L, respectively. The results showed that ethanol could be preferentially degraded in the absence of PS and inhibit BTEX biodegradation. However, BTEX could be preferentially removed prior to ethanol in all aquifer materials used at ambient temperature, when PS was added at a PS/BTEX molar ratio of 150. Over 94% BTEX in sand, dolomite, and granite soil was preferentially removed with the first-order decay rate constants of 0.890-2.703day-1 within the first ~ 10days, followed by calcareous and basalt soil at the constants of 0.123-0.371day-1. Ethanol could compete with BTEX for sulfate radical at the first-order decay rate constants of 0.005-0.060day-1 for the first 25days, which was slower than that of BTEX. The pH quickly decreased to < 2.5 in dolomite, sand, and granite soil, but maintained > 6.2 in calcareous soil. Rich organic matter in calcareous and basalt soil had an inhibition effect on BTEX oxidation by PS. The pH buffer in calcareous soil may imply the potential of PS oxidation combined with bioremediation in carbonate rock regions.

Impact of coolant temperature on the combustion characteristics and emissions of a stratified-charge direct-injection spark-ignition engine fueled with E30

The direct injection spark ignition (DISI) engine has received considerable attention due to its potential to increase the power density of traditional spark ignition engines while significantly improving fuel economy through lean, unthrottled combustion. However, the market introduction of DISI engines operated in a lean combustion mode is inhibited by their unsatisfactory emissions, especially during cold start conditions that make proper mixture formation more challenging. Ethanol-blended gasoline, now a widely used fuel, makes the cold start of a DISI engine more difficult, leading to higher HC and soot emissions because of the high latent heat of vaporization of ethanol relative to gasoline. This work investigated the impact of coolant temperature on the characteristics of combustion and emissions in a stratified-charge DISI engine fueled with an E30 fuel (i.e. 30% ethanol in gasoline), while the coolant temperature was alternated between four levels (45, 60, 75, and 90 °C) to simulate different conditions throughout the warm-up process. The experiments showed that the coolant temperature affected the post-spark inflammation time, as well as the speed, intensity, and stability of the combustion process in the engine. When the coolant temperature rose, the engine produced more NOX and less CO, PM and HC. In addition, high-speed direct photography was used to obtain crank-angle resolved images of fuel sprays and flames in the cylinder. As the coolant temperature rose, the liquid spray lengths became shorter, reducing the possibility of wall wetting, and reduced irradiance from soot particles also indicated less non-premixed combustion. The in-cylinder imaging results are consistent with the observed combustion and emission characteristics and shed light on the underlying processes. Some potential solutions to the emissions challenges faced here could be either raising in-cylinder temperatures by using trapped residuals or modifying the injection schedule, for example by increasing the number of injections or to inject later in the cycle into a higher-density environment.

Transcription profiles in BEAS-2B cells exposed to organic extracts from particulate emissions produced by a port-fuel injection vehicle, fueled with conventional fossil gasoline and gasoline-ethanol blend

Emissions from road traffic are among the major contributors to air pollution worldwide and represent a serious environmental health risk. Although traffic-related pollution has been most commonly associated with diesel engines, increasing evidence suggests that gasoline engines also produce a considerable amount of potentially hazardous particulate matter (PM). The primary objective of this study was to compare the intrinsic toxic properties of the organic components of PM, generated by a conventional gasoline engine fueled with neat gasoline (E0), or gasoline-ethanol blend (15 % ethanol, v/v, E15). Our results showed that while E15 has produced, compared to gasoline and per kg of fuel, comparable particle mass (μg PM/kg fuel) and slightly more particles by number, the organic extract from the particulate matter produced by E15 contained a larger amount of harmful polycyclic aromatic hydrocarbons (PAHs), as determined by the chemical analysis. To examine the toxicity, we monitored genome-wide gene expression changes in human lung BEAS-2B cells, exposed for 4 h and 24 h to a subtoxic dose of each PM extract. After 4 h exposure, numerous dysregulated genes and processes such as oxidative stress, lipid and steroid metabolism, PPARα signaling and immune response, were found to be common for both extract treatments. On the other hand, 24 h exposure resulted in more distinctive gene expression patterns. Although we identified several common modulated processes indicating the metabolism of PAHs and activation of aryl hydrocarbon receptor (AhR), E15 specifically dysregulated a variety of other genes and pathways related to cancer promotion and progression. Overall, our findings suggest that the ethanol addition to gasoline changed the intrinsic properties of PM emissions and increased the PAH content in PM organic extract, thus contributing to a more extensive toxic response particularly after 24 h exposure in BEAS-2B cells.

Experimental Study on Elastomer Compatibility with Ethanol-Gasoline Blends

Experimental Study on Elastomer Compatibility with Ethanol-Gasoline Blends

Volatility and physicochemical properties of gasoline-ethanol blends with gasoline RON-based 88, 90, and 92

A binary set of gasoline-ethanol (GE) blends from three types of gasoline’s research octane number (RON), i.e., RON 88, RON 90, and RON 92, were formulated. Herein, the volatility characteristics, i.e., vapor pressure and distillation behavior were measured. Also, physiochemical properties, i.e., density and RON for each blend and oxygenating compounds influence from ethanol, were discussed. The obtained result revealed that the vapor pressure of GE blends is highly affected by non-ideal vapor-liquid equilibrium mixture. The initial boiling point of GE blends would gradually increase as the higher ethanol’s concentration. However, the final boiling point of the GE blends never exceeds the final boiling point of the pristine gasoline, yet never less than the final boiling point of pristine ethanol. Furthermore, RON, oxygenate content, and density, showed a linear increment curve by increasing ethanol content on each gasoline type. Finally, the results showed that it might be advantageous to use ethanol to provide the added value of gasoline RON 88, RON 90, or RON 92 to form a new gasoline product by considering a confident RON and the limitations for high and low volatility.

Prediction of ethanol-gasoline blend fuelled spark ignition engine performance using dimensional analysis

ABSTRACT Ethanol is blended with pure gasoline for use as a fuel in a gasoline engine. It is required to conduct physical tests on engines to observe the engine performance for these fuel blends. However, mathematical equations provide a quick, effective, and accurate alternate for physical tests. It may not be possible to develop the mathematical relations for the specific operating conditions of engine and fuel. It is possible to use dimensional analysis approach to develop mathematical model. Dimensional analysis approach is used in this research work for deriving the mathematical correlations of Indicated Mean Effective Pressure, Brake Power, Indicated Power, and Brake Specific Fuel Consumption as engine performance parameters. Their relations are established with engine speed, load on engine, calorific value of fuel fractions, and clearance volume of engine as independent parameters. Buckingham π theorem is used for formulating the relations having proportionality sign showing the possible relations of each dependent parameter with all four independent parameters. Regression analysis is used for eliminating proportionality signs from the equations developed. Mathematical relations developed by the dimensional analysis are accurate. Root Mean Square errors have noted a minimum of 4.19 for Brake Specific Fuel Consumption and a maximum 8.56 for Brake Power. The average percentage errors are less than 1%.

Effect of operation under lean conditions on NOx emissions and fuel consumption fueling an SI engine with hydrous ethanol–gasoline blends enhanced with synthesis gas

For the purpose of creating a clean environment, achieving higher engine efficiency, and complying with increasingly strict emission regulations, many methods have been developed to enhance SI engines performance and decrease their pollutant emissions. In this study, the effects of using hydrous ethanol–gasoline blends and synthesis gas addition on NOx emissions and fuel consumption under lean and ultra-lean conditions (i.e. at air/fuel equivalence ratios (λ) = 1.13, 1.26 and 1.46) were investigated using a Spark-Ignition (SI) engine. The engine was fuelled with a Saudi Arabian gasoline grade (RON91), mixed with 5 % and 10 % of hydrous ethanol containing different water concentrations (5 %, 10 %, 30 %, and 40 %). An on-board plasma fuel reformer was employed for the production of hydrogen-rich syngas via the partial oxidation of gasoline. The results revealed the evident positive effect of operating under lean conditions using hydrous ethanol–gasoline blends on reducing the NOx emissions. In addition, NOx emissions decreased with increasing the air/fuel ratio to reach the minimum at the highest lean condition. However, fuel consumption increased with equivalence air/fuel ratio from low-lean at λ = 1.13 to high lean at λ = 1.46 conditions. Syngas addition to the fuel blend under lean conditions resulted in further reduction of NOx emissions but increased the overall fuel consumption. The results showed that up to 4 % of water enrichment of hydrous-gasoline blend can effectively enhance the engine thermal efficiency and reduce NOx emission.

Experimental analysis of evaporative emissions of ethanol-blended gasoline in automotive tanks at different temperature conditions

Automobiles are major sources of Volatile Organic Compounds (VOCs) and Very Volatile Organic Compounds (VVOCs), which are emitted not only from their tailpipes while running but also as evaporative emissions from gasoline fueled vehicle tanks and supply systems; these emissions are the main source of pollution for both standard and hybrid vehicles. VOCs and VVOCs can have significant effects on human health and environment, so emissions are subject to many regulations, both European and international, that are becoming increasingly stringent every year. In this paper, an experimental activity has been carried out to evaluate the fuel vapor generation from gasoline-filled fuel tanks. These experimental tests have been conducted by means of a Variable Temperature mini-SHED in Stellantis N.V. laboratories, at the Pomigliano Technical Center, in Italy. Different conditions of temperature and filling levels have been analyzed by monitoring the fuel vapors coming from the tank to the carbon canister. Tests have been divided in two groups with both constant and variable temperatures, by following standard temperature cycles, defined by regulations. Results are presented in terms of vapor temperature profiles and canister mass variation; they demonstrate the high influence of the environment temperature and of the filling levels on the emission.

Fuel Consumption and Emissions Analysis of a Light Vehicle Fuelled with Two Ethanol–Gasoline Blends in Urban Driving Conditions of Lima Metropolitana

We present a comparative study of fuel consumption, emissions factors, and vehicle-specific power of a light vehicle operating with two gasoline–ethanol blends as fuel: commercial gasohol (E7.8) and an alternative mix with 10% v/v of ethanol (E10). For this purpose, a vehicle in the city’s fleet was equipped with a central system of data acquisition, whose main function was to capture second-by-second data of the air intake of the engine, the emissions concentration levels in the exhaust, the distance traveled, vehicle speed, and environmental conditions during testing. The measuring campaign was carried out in the city of Lima Metropolitana. Fuel consumption was calculated indirectly, using air intake measurements. The vehicle’s engine emissions were analysed using the mass flow rates of CO2, CO, HC, and NOx, as well as the vehicle-specific power. The results show that, in traffic conditions, the change in fuels does not affect the consumption. On the other hand, a correlation was found between the vehicle-specific power and the emissions mass flow. During the comparison between fuels, the results showed an increase in the mass flow standard deviation when using E10.

Characterization of vibration and noise pollution of SI engine fueled with magnetized ethanol–gasoline blends by time–frequency methods

The purpose of the present study was to investigate the effects of magnetized ethanol–gasoline fuel blends on the vibration and sound status of a single-cylinder gasoline engine. Totally 36 tests were conducted including two factors: ethanol (blended by gasoline with share of 0, 5, 10, and 20%) and magnetic field intensity (0, 5300, and 7000 G) at three replications as a factorial experiment based on completely randomized design. The sound signals of the engine at 10 cm distance from the driver’s ear were recorded and its engine vibration was measured in Z direction. The results of statistical analysis of vibration and sound data showed significant effects of both factors on the vibration and sound signals. The maximum sound pressure level with averages of 88.41 belonged to pure gasoline and magnetic intensity of 7000 G and minimum value (78.94 dB) belonged to 10% ethanol in the blended fuel and magnetic intensity of 5300 G. The driver can operate the engine for 10–20% ethanol shares with all studied magnetic intensities without use of any ear protector. In the presence of magnetic field, vibration decreased by increasing ethanol up to 10%. The maximum amount of vibration in frequency domain obtained without using magnetic field. For 5300 G magnetic intensity, the least amount of vibration was observed for all frequencies.

Secondary aerosol formation from a Chinese gasoline vehicle: Impacts of fuel (E10, gasoline) and driving conditions (idling, cruising)

Chassis dynamometer experiments were conducted to investigate the effect of vehicle speed and usage of ethanol-blended gasoline (E10) on formation and evolution of gasoline vehicular secondary organic aerosol (SOA) using a Gothenburg Potential Aerosol Mass (Go: PAM) reactor. The SOA forms rapidly, and its concentration exceeds that of primary organic aerosol (POA) at an equivalent photochemical age (EPA) of ~1 day. The particle effective densities grow from 0.62 ± 0.02 g cm−3 to 1.43 ± 0.07 g cm−3 with increased hydroxyl radical (OH) exposure. The maximum SOA production under idling conditions (4259–7394 mg kg-fuel−1) is ~20 times greater than under cruising conditions. There was no statistical difference between SOA formation from pure gasoline and its formation from E10. The slopes in Van Krevelen diagram indicate that the formation pathways of bulk SOA includes the addition of both alcohol/peroxide functional groups and carboxylic acid formation from fragmentation. A closure estimation of SOA based on bottom-up and top-down methods shows that only 16%–38% of the measured SOA can be explained by the oxidation of measured volatile organic compounds (VOCs), suggesting the existence of missing precursors, e.g. unmeasured VOCs and probably semivolatile or intermediate volatile organic compounds (S/IVOCs). Our results suggest that applying parameters obtained from unified driving cycles to model SOA concentrations may lead to large discrepancies between modeled and ambient vehicular SOA. No reduction in vehicular `SOA production is realized by replacing normal gasoline with E10.

Characterisation of spark plug deposits of an SI engine fuelled with gasoline-ethanol blends

This work investigates the effect of gasoline-ethanol blends on spark plug deposits. The mass of deposits rapidly increases in all blends at first, then stabilises to an equilibrium state. The steady-state deposit mass for fuel E0, E5, E10, and E15 is found to be 1.0994, 1.6890, 2.2432, and 3.1420 g, respectively. The scanning electron microscope results show that the deposits are porous and formed by agglomeration of fine particles. However, as the ethanol fraction increases, the microstructures of the deposits become denser and more compact. The maximum particle diameter for E0 is found to be 5.71 μm while it increases to 13.61 μm for E15. The energy-dispersive X-ray spectroscopy results show the presence of metal elements such as iron, zinc, aluminium, copper, and nickel, and other elements such as calcium, phosphorus, sulphur, and sodium. The deposits conductive in nature promote the chance of side sparking.